1 /*
2 * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotCacheAccess.hpp"
27 #include "cds/aotClassInitializer.hpp"
28 #include "cds/aotClassLocation.hpp"
29 #include "cds/aotConstantPoolResolver.hpp"
30 #include "cds/aotLogging.hpp"
31 #include "cds/aotMetaspace.hpp"
32 #include "cds/aotOopChecker.hpp"
33 #include "cds/aotReferenceObjSupport.hpp"
34 #include "cds/archiveBuilder.hpp"
35 #include "cds/archiveHeapLoader.hpp"
36 #include "cds/archiveHeapWriter.hpp"
37 #include "cds/archiveUtils.hpp"
38 #include "cds/cdsConfig.hpp"
39 #include "cds/cdsEnumKlass.hpp"
40 #include "cds/cdsHeapVerifier.hpp"
41 #include "cds/heapShared.hpp"
42 #include "cds/regeneratedClasses.hpp"
43 #include "classfile/classLoaderData.hpp"
44 #include "classfile/javaClasses.inline.hpp"
45 #include "classfile/modules.hpp"
46 #include "classfile/stringTable.hpp"
47 #include "classfile/symbolTable.hpp"
48 #include "classfile/systemDictionary.hpp"
49 #include "classfile/systemDictionaryShared.hpp"
50 #include "classfile/vmClasses.hpp"
51 #include "classfile/vmSymbols.hpp"
52 #include "gc/shared/collectedHeap.hpp"
53 #include "gc/shared/gcLocker.hpp"
54 #include "gc/shared/gcVMOperations.hpp"
55 #include "logging/log.hpp"
56 #include "logging/logStream.hpp"
57 #include "memory/iterator.inline.hpp"
58 #include "memory/resourceArea.hpp"
59 #include "memory/universe.hpp"
60 #include "oops/compressedOops.inline.hpp"
61 #include "oops/fieldStreams.inline.hpp"
62 #include "oops/objArrayOop.inline.hpp"
63 #include "oops/oop.inline.hpp"
64 #include "oops/oopHandle.inline.hpp"
65 #include "oops/typeArrayOop.inline.hpp"
66 #include "prims/jvmtiExport.hpp"
67 #include "runtime/arguments.hpp"
68 #include "runtime/fieldDescriptor.inline.hpp"
69 #include "runtime/init.hpp"
70 #include "runtime/javaCalls.hpp"
71 #include "runtime/mutexLocker.hpp"
72 #include "runtime/safepointVerifiers.hpp"
73 #include "utilities/bitMap.inline.hpp"
74 #include "utilities/copy.hpp"
75 #if INCLUDE_G1GC
76 #include "gc/g1/g1CollectedHeap.hpp"
77 #endif
78
79 #if INCLUDE_CDS_JAVA_HEAP
80
81 struct ArchivableStaticFieldInfo {
82 const char* klass_name;
83 const char* field_name;
84 InstanceKlass* klass;
85 int offset;
86 BasicType type;
87
88 ArchivableStaticFieldInfo(const char* k, const char* f)
89 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
90
91 bool valid() {
92 return klass_name != nullptr;
93 }
94 };
95
96 class HeapShared::ContextMark : public StackObj {
97 ResourceMark rm;
98 public:
99 ContextMark(const char* c) : rm{} {
100 _context->push(c);
101 }
102 ~ContextMark() {
103 _context->pop();
104 }
105 };
106
107 DumpedInternedStrings *HeapShared::_dumped_interned_strings = nullptr;
108
109 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
110 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
111 size_t HeapShared::_total_obj_count;
112 size_t HeapShared::_total_obj_size;
113
114 #ifndef PRODUCT
115 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
116 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
117 static const char* _test_class_name = nullptr;
118 static Klass* _test_class = nullptr;
119 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
120 #endif
121
122
123 //
124 // If you add new entries to the following tables, you should know what you're doing!
125 //
126
127 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
128 {"java/lang/Integer$IntegerCache", "archivedCache"},
129 {"java/lang/Long$LongCache", "archivedCache"},
130 {"java/lang/Byte$ByteCache", "archivedCache"},
131 {"java/lang/Short$ShortCache", "archivedCache"},
132 {"java/lang/Character$CharacterCache", "archivedCache"},
133 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
134 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
135 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
136 {"java/util/ImmutableCollections", "archivedObjects"},
137 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
138 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
139 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
140 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
141
142 #ifndef PRODUCT
143 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
144 #endif
145 {nullptr, nullptr},
146 };
147
148 // full module graph
149 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
150 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
151 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
152 {"java/lang/Module$ArchivedData", "archivedData"},
153 {nullptr, nullptr},
154 };
155
156 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
157 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
158 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_pending_roots = nullptr;
159 GrowableArrayCHeap<const char*, mtClassShared>* HeapShared::_context = nullptr;
160 GrowableArrayCHeap<OopHandle, mtClassShared>* HeapShared::_root_segments = nullptr;
161 int HeapShared::_root_segment_max_size_elems;
162 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
163 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
164
165 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
166 for (int i = 0; fields[i].valid(); i++) {
167 if (fields[i].klass == ik) {
168 return true;
169 }
170 }
171 return false;
172 }
173
174 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
175 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
176 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
177 }
178
179 oop HeapShared::CachedOopInfo::orig_referrer() const {
180 return _orig_referrer.resolve();
181 }
182
183 unsigned HeapShared::oop_hash(oop const& p) {
184 assert(SafepointSynchronize::is_at_safepoint() ||
185 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
186 // Do not call p->identity_hash() as that will update the
187 // object header.
188 return primitive_hash(cast_from_oop<intptr_t>(p));
189 }
190
191 unsigned int HeapShared::oop_handle_hash_raw(const OopHandle& oh) {
192 return oop_hash(oh.resolve());
193 }
194
195 unsigned int HeapShared::oop_handle_hash(const OopHandle& oh) {
196 oop o = oh.resolve();
197 if (o == nullptr) {
198 return 0;
199 } else {
200 return o->identity_hash();
201 }
202 }
203
204 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
205 return a.resolve() == b.resolve();
206 }
207
208 static void reset_states(oop obj, TRAPS) {
209 Handle h_obj(THREAD, obj);
210 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
211 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
212 Symbol* method_sig = vmSymbols::void_method_signature();
213
214 while (klass != nullptr) {
215 Method* method = klass->find_method(method_name, method_sig);
216 if (method != nullptr) {
217 assert(method->is_private(), "must be");
218 if (log_is_enabled(Debug, aot)) {
219 ResourceMark rm(THREAD);
220 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
221 }
222 JavaValue result(T_VOID);
223 JavaCalls::call_special(&result, h_obj, klass,
224 method_name, method_sig, CHECK);
225 }
226 klass = klass->super();
227 }
228 }
229
230 void HeapShared::reset_archived_object_states(TRAPS) {
231 assert(CDSConfig::is_dumping_heap(), "dump-time only");
232 log_debug(aot)("Resetting platform loader");
233 reset_states(SystemDictionary::java_platform_loader(), CHECK);
234 log_debug(aot)("Resetting system loader");
235 reset_states(SystemDictionary::java_system_loader(), CHECK);
236
237 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
238 // directly used for class loading, but rather is used by the core library
239 // to keep track of resources, etc, loaded by the null class loader.
240 //
241 // Note, this object is non-null, and is not the same as
242 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
243 // which is null.
244 log_debug(aot)("Resetting boot loader");
245 JavaValue result(T_OBJECT);
246 JavaCalls::call_static(&result,
247 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
248 vmSymbols::bootLoader_name(),
249 vmSymbols::void_BuiltinClassLoader_signature(),
250 CHECK);
251 Handle boot_loader(THREAD, result.get_oop());
252 reset_states(boot_loader(), CHECK);
253 }
254
255 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
256
257 bool HeapShared::has_been_archived(oop obj) {
258 assert(CDSConfig::is_dumping_heap(), "dump-time only");
259 OopHandle oh(&obj);
260 return archived_object_cache()->get(oh) != nullptr;
261 }
262
263 int HeapShared::append_root(oop obj) {
264 assert(CDSConfig::is_dumping_heap(), "dump-time only");
265 if (obj != nullptr) {
266 assert(has_been_archived(obj), "must be");
267 }
268 // No GC should happen since we aren't scanning _pending_roots.
269 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
270
271 OopHandle oh(Universe::vm_global(), obj);
272 return _pending_roots->append(oh);
273 }
274
275 objArrayOop HeapShared::root_segment(int segment_idx) {
276 if (CDSConfig::is_dumping_heap() && !CDSConfig::is_dumping_final_static_archive()) {
277 assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
278 } else {
279 assert(CDSConfig::is_using_archive(), "must be");
280 }
281
282 objArrayOop segment = (objArrayOop)_root_segments->at(segment_idx).resolve();
283 assert(segment != nullptr, "should have been initialized");
284 return segment;
285 }
286
287 class OrigToScratchObjectTable: public HashTable<OopHandle, OopHandle,
288 36137, // prime number
289 AnyObj::C_HEAP,
290 mtClassShared,
291 HeapShared::oop_handle_hash,
292 HeapShared::oop_handle_equals> {};
293
294 static OrigToScratchObjectTable* _orig_to_scratch_object_table = nullptr;
295
296 void HeapShared::track_scratch_object(oop orig_obj, oop scratch_obj) {
297 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
298 if (_orig_to_scratch_object_table == nullptr) {
299 _orig_to_scratch_object_table = new (mtClass)OrigToScratchObjectTable();
300 }
301
302 OopHandle orig_h(Universe::vm_global(), orig_obj);
303 OopHandle scratch_h(Universe::vm_global(), scratch_obj);
304 _orig_to_scratch_object_table->put_when_absent(orig_h, scratch_h);
305 }
306
307 oop HeapShared::orig_to_scratch_object(oop orig_obj) {
308 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
309 if (_orig_to_scratch_object_table != nullptr) {
310 OopHandle orig(&orig_obj);
311 OopHandle* v = _orig_to_scratch_object_table->get(orig);
312 if (v != nullptr) {
313 return v->resolve();
314 }
315 }
316 return nullptr;
317 }
318
319 // Permanent oops are used to support AOT-compiled methods, which may have in-line references
320 // to Strings and MH oops.
321 //
322 // At runtime, these oops are stored in _runtime_permanent_oops (which keeps them alive forever)
323 // and are accssed vis AOTCacheAccess::get_archived_object(int).
324 struct PermanentOopInfo {
325 int _index; // Gets assigned only if HeapShared::get_archived_object_permanent_index() has been called on the object
326 int _heap_offset; // Offset of the object from the bottom of the archived heap.
327 PermanentOopInfo(int index, int heap_offset) : _index(index), _heap_offset(heap_offset) {}
328 };
329
330 class PermanentOopTable: public HashTable<OopHandle, PermanentOopInfo,
331 36137, // prime number
332 AnyObj::C_HEAP,
333 mtClassShared,
334 HeapShared::oop_handle_hash,
335 HeapShared::oop_handle_equals> {};
336
337 static int _dumptime_permanent_oop_count = 0;
338 static PermanentOopTable* _dumptime_permanent_oop_table = nullptr;
339 static GrowableArrayCHeap<OopHandle, mtClassShared>* _runtime_permanent_oops = nullptr;
340
341 // ArchiveHeapWriter adds each archived heap object to _dumptime_permanent_oop_table,
342 // so we can remember their offset (from the bottom of the archived heap).
343 void HeapShared::add_to_permanent_oop_table(oop obj, int offset) {
344 assert_at_safepoint();
345 if (_dumptime_permanent_oop_table == nullptr) {
346 _dumptime_permanent_oop_table = new (mtClass)PermanentOopTable();
347 }
348
349 PermanentOopInfo info(-1, offset);
350 OopHandle oh(Universe::vm_global(), obj);
351 _dumptime_permanent_oop_table->put_when_absent(oh, info);
352 }
353
354 // A permanent index is assigned to an archived object ONLY when
355 // the AOT compiler calls this function.
356 int HeapShared::get_archived_object_permanent_index(oop obj) {
357 MutexLocker ml(ArchivedObjectTables_lock, Mutex::_no_safepoint_check_flag);
358
359 if (!CDSConfig::is_dumping_heap()) {
360 return -1; // Called by the Leyden old workflow
361 }
362 if (_dumptime_permanent_oop_table == nullptr) {
363 return -1;
364 }
365
366 if (_orig_to_scratch_object_table != nullptr) {
367 OopHandle orig(&obj);
368 OopHandle* v = _orig_to_scratch_object_table->get(orig);
369 if (v != nullptr) {
370 obj = v->resolve();
371 }
372 }
373
374 OopHandle tmp(&obj);
375 PermanentOopInfo* info = _dumptime_permanent_oop_table->get(tmp);
376 if (info == nullptr) {
377 return -1;
378 } else {
379 if (info->_index < 0) {
380 info->_index = _dumptime_permanent_oop_count++;
381 }
382 return info->_index;
383 }
384 }
385
386 oop HeapShared::get_archived_object(int permanent_index) {
387 assert(permanent_index >= 0, "sanity");
388 assert(ArchiveHeapLoader::is_in_use(), "sanity");
389 assert(_runtime_permanent_oops != nullptr, "sanity");
390
391 return _runtime_permanent_oops->at(permanent_index).resolve();
392 }
393
394 // Remember all archived heap objects that have a permanent index.
395 // table[i] = offset of oop whose permanent index is i.
396 void CachedCodeDirectoryInternal::dumptime_init_internal() {
397 const int count = _dumptime_permanent_oop_count;
398 if (count == 0) {
399 // Avoid confusing CDS code with zero-sized tables, just return.
400 log_info(cds)("No permanent oops");
401 _permanent_oop_count = count;
402 _permanent_oop_offsets = nullptr;
403 return;
404 }
405
406 int* table = (int*)AOTCacheAccess::allocate_aot_code_region(count * sizeof(int));
407 for (int i = 0; i < count; i++) {
408 table[count] = -1;
409 }
410 _dumptime_permanent_oop_table->iterate([&](OopHandle o, PermanentOopInfo& info) {
411 int index = info._index;
412 if (index >= 0) {
413 assert(index < count, "sanity");
414 table[index] = info._heap_offset;
415 }
416 return true; // continue
417 });
418
419 for (int i = 0; i < count; i++) {
420 assert(table[i] >= 0, "must be");
421 }
422
423 log_info(cds)("Dumped %d permanent oops", count);
424
425 _permanent_oop_count = count;
426 AOTCacheAccess::set_pointer(&_permanent_oop_offsets, table);
427 }
428
429 // This is called during the bootstrap of the production run, before any GC can happen.
430 // Record each permanent oop in a OopHandle for GC safety.
431 void CachedCodeDirectoryInternal::runtime_init_internal() {
432 int count = _permanent_oop_count;
433 int* table = _permanent_oop_offsets;
434 _runtime_permanent_oops = new GrowableArrayCHeap<OopHandle, mtClassShared>();
435 for (int i = 0; i < count; i++) {
436 oop obj = ArchiveHeapLoader::oop_from_offset(table[i]);
437 OopHandle oh(Universe::vm_global(), obj);
438 _runtime_permanent_oops->append(oh);
439 }
440 };
441
442 void HeapShared::get_segment_indexes(int idx, int& seg_idx, int& int_idx) {
443 assert(_root_segment_max_size_elems > 0, "sanity");
444
445 // Try to avoid divisions for the common case.
446 if (idx < _root_segment_max_size_elems) {
447 seg_idx = 0;
448 int_idx = idx;
449 } else {
450 seg_idx = idx / _root_segment_max_size_elems;
451 int_idx = idx % _root_segment_max_size_elems;
452 }
453
454 assert(idx == seg_idx * _root_segment_max_size_elems + int_idx,
455 "sanity: %d index maps to %d segment and %d internal", idx, seg_idx, int_idx);
456 }
457
458 // Returns an objArray that contains all the roots of the archived objects
459 oop HeapShared::get_root(int index, bool clear) {
460 assert(index >= 0, "sanity");
461 assert(!CDSConfig::is_dumping_heap() && CDSConfig::is_using_archive(), "runtime only");
462 assert(!_root_segments->is_empty(), "must have loaded shared heap");
463 int seg_idx, int_idx;
464 get_segment_indexes(index, seg_idx, int_idx);
465 oop result = root_segment(seg_idx)->obj_at(int_idx);
466 if (clear) {
467 clear_root(index);
468 }
469 return result;
470 }
471
472 void HeapShared::clear_root(int index) {
473 assert(index >= 0, "sanity");
474 assert(CDSConfig::is_using_archive(), "must be");
475 if (ArchiveHeapLoader::is_in_use()) {
476 int seg_idx, int_idx;
477 get_segment_indexes(index, seg_idx, int_idx);
478 if (log_is_enabled(Debug, aot, heap)) {
479 oop old = root_segment(seg_idx)->obj_at(int_idx);
480 log_debug(aot, heap)("Clearing root %d: was " PTR_FORMAT, index, p2i(old));
481 }
482 root_segment(seg_idx)->obj_at_put(int_idx, nullptr);
483 }
484 }
485
486 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
487 assert(CDSConfig::is_dumping_heap(), "dump-time only");
488
489 assert(!obj->is_stackChunk(), "do not archive stack chunks");
490 if (has_been_archived(obj)) {
491 return true;
492 }
493
494 if (ArchiveHeapWriter::is_too_large_to_archive(obj->size())) {
495 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
496 p2i(obj), obj->size());
497 debug_trace();
498 return false;
499 } else {
500 AOTOopChecker::check(obj); // Make sure contents of this oop are safe.
501
502 count_allocation(obj->size());
503 ArchiveHeapWriter::add_source_obj(obj);
504 CachedOopInfo info = make_cached_oop_info(obj, referrer);
505
506 OopHandle oh(Universe::vm_global(), obj);
507 archived_object_cache()->put_when_absent(oh, info);
508 archived_object_cache()->maybe_grow();
509 mark_native_pointers(obj);
510
511 Klass* k = obj->klass();
512 if (k->is_instance_klass()) {
513 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
514 // This ensures that during the production run, whenever Java code sees a cached object
515 // of type X, we know that X is already initialized. (see TODO comment below ...)
516
517 if (InstanceKlass::cast(k)->is_enum_subclass()
518 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
519 // we must store them as AOT-initialized.
520 || (subgraph_info == _dump_time_special_subgraph))
521 // TODO: we do this only for the special subgraph for now. Extending this to
522 // other subgraphs would require more refactoring of the core library (such as
523 // move some initialization logic into runtimeSetup()).
524 //
525 // For the other subgraphs, we have a weaker mechanism to ensure that
526 // all classes in a subgraph are initialized before the subgraph is programmatically
527 // returned from jdk.internal.misc.CDS::initializeFromArchive().
528 // See HeapShared::initialize_from_archived_subgraph().
529 {
530 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
531 }
532
533 if (java_lang_Class::is_instance(obj)) {
534 Klass* mirror_k = java_lang_Class::as_Klass(obj);
535 if (mirror_k != nullptr) {
536 AOTArtifactFinder::add_cached_class(mirror_k);
537 }
538 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
539 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
540 if (m != nullptr) {
541 if (RegeneratedClasses::has_been_regenerated(m)) {
542 m = RegeneratedClasses::get_regenerated_object(m);
543 }
544 InstanceKlass* method_holder = m->method_holder();
545 AOTArtifactFinder::add_cached_class(method_holder);
546 }
547 }
548 }
549
550 if (log_is_enabled(Debug, aot, heap)) {
551 ResourceMark rm;
552 LogTarget(Debug, aot, heap) log;
553 LogStream out(log);
554 out.print("Archived heap object " PTR_FORMAT " : %s ",
555 p2i(obj), obj->klass()->external_name());
556 if (java_lang_Class::is_instance(obj)) {
557 Klass* k = java_lang_Class::as_Klass(obj);
558 if (k != nullptr) {
559 out.print("%s", k->external_name());
560 } else {
561 out.print("primitive");
562 }
563 }
564 out.cr();
565 }
566
567 return true;
568 }
569 }
570
571 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
572 36137, // prime number
573 AnyObj::C_HEAP,
574 mtClassShared> {
575 public:
576 oop get_oop(MetaspaceObj* ptr) {
577 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
578 OopHandle* handle = get(ptr);
579 if (handle != nullptr) {
580 return handle->resolve();
581 } else {
582 return nullptr;
583 }
584 }
585 void set_oop(MetaspaceObj* ptr, oop o) {
586 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
587 OopHandle handle(Universe::vm_global(), o);
588 bool is_new = put(ptr, handle);
589 assert(is_new, "cannot set twice");
590 }
591 void remove_oop(MetaspaceObj* ptr) {
592 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
593 OopHandle* handle = get(ptr);
594 if (handle != nullptr) {
595 handle->release(Universe::vm_global());
596 remove(ptr);
597 }
598 }
599 };
600
601 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
602 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
603 _scratch_objects_table->set_oop(src, dest);
604 }
605 }
606
607 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
608 return (objArrayOop)_scratch_objects_table->get_oop(src);
609 }
610
611 void HeapShared::init_dumping() {
612 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
613 _pending_roots = new GrowableArrayCHeap<OopHandle, mtClassShared>(500);
614 }
615
616 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
617 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
618 BasicType bt = (BasicType)i;
619 if (!is_reference_type(bt)) {
620 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
621 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
622 track_scratch_object(Universe::java_mirror(bt), m);
623 }
624 }
625 }
626
627 // Given java_mirror that represents a (primitive or reference) type T,
628 // return the "scratch" version that represents the same type T.
629 // Note that if java_mirror will be returned if it's already a
630 // scratch mirror.
631 //
632 // See java_lang_Class::create_scratch_mirror() for more info.
633 oop HeapShared::scratch_java_mirror(oop java_mirror) {
634 assert(java_lang_Class::is_instance(java_mirror), "must be");
635
636 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
637 BasicType bt = (BasicType)i;
638 if (!is_reference_type(bt)) {
639 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
640 return java_mirror;
641 }
642 }
643 }
644
645 if (java_lang_Class::is_primitive(java_mirror)) {
646 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
647 } else {
648 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
649 }
650 }
651
652 oop HeapShared::scratch_java_mirror(BasicType t) {
653 assert((uint)t < T_VOID+1, "range check");
654 assert(!is_reference_type(t), "sanity");
655 return _scratch_basic_type_mirrors[t].resolve();
656 }
657
658 oop HeapShared::scratch_java_mirror(Klass* k) {
659 return _scratch_objects_table->get_oop(k);
660 }
661
662 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
663 track_scratch_object(k->java_mirror(), mirror);
664 _scratch_objects_table->set_oop(k, mirror);
665 }
666
667 void HeapShared::remove_scratch_objects(Klass* k) {
668 // Klass is being deallocated. Java mirror can still be alive, and it should not
669 // point to dead klass. We need to break the link from mirror to the Klass.
670 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
671 oop mirror = _scratch_objects_table->get_oop(k);
672 if (mirror != nullptr) {
673 java_lang_Class::set_klass(mirror, nullptr);
674 }
675 _scratch_objects_table->remove_oop(k);
676 if (k->is_instance_klass()) {
677 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
678 }
679 if (mirror != nullptr) {
680 OopHandle tmp(&mirror);
681 OopHandle* v = _orig_to_scratch_object_table->get(tmp);
682 if (v != nullptr) {
683 oop scratch_mirror = v->resolve();
684 java_lang_Class::set_klass(scratch_mirror, nullptr);
685 _orig_to_scratch_object_table->remove(tmp);
686 }
687 }
688 }
689
690 //TODO: we eventually want a more direct test for these kinds of things.
691 //For example the JVM could record some bit of context from the creation
692 //of the klass, such as who called the hidden class factory. Using
693 //string compares on names is fragile and will break as soon as somebody
694 //changes the names in the JDK code. See discussion in JDK-8342481 for
695 //related ideas about marking AOT-related classes.
696 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
697 return ik->is_hidden() &&
698 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
699 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
700 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
701 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
702 }
703
704 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
705 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
706 }
707
708 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
709 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
710 }
711
712 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
713 return CDSConfig::is_dumping_method_handles() &&
714 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
715 }
716
717
718 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
719 ik->set_has_aot_initialized_mirror();
720
721 oop orig_mirror;
722 if (RegeneratedClasses::is_regenerated_object(ik)) {
723 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
724 precond(orig_ik->is_initialized());
725 orig_mirror = orig_ik->java_mirror();
726 } else {
727 precond(ik->is_initialized());
728 orig_mirror = ik->java_mirror();
729 }
730
731 oop m = scratch_java_mirror(ik);
732 int nfields = 0;
733 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
734 if (fs.access_flags().is_static()) {
735 fieldDescriptor& fd = fs.field_descriptor();
736 int offset = fd.offset();
737 switch (fd.field_type()) {
738 case T_OBJECT:
739 case T_ARRAY:
740 {
741 oop field_obj = orig_mirror->obj_field(offset);
742 m->obj_field_put(offset, field_obj);
743 if (field_obj != nullptr) {
744 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
745 assert(success, "sanity");
746 }
747 }
748 break;
749 case T_BOOLEAN:
750 m->bool_field_put(offset, orig_mirror->bool_field(offset));
751 break;
752 case T_BYTE:
753 m->byte_field_put(offset, orig_mirror->byte_field(offset));
754 break;
755 case T_SHORT:
756 m->short_field_put(offset, orig_mirror->short_field(offset));
757 break;
758 case T_CHAR:
759 m->char_field_put(offset, orig_mirror->char_field(offset));
760 break;
761 case T_INT:
762 m->int_field_put(offset, orig_mirror->int_field(offset));
763 break;
764 case T_LONG:
765 m->long_field_put(offset, orig_mirror->long_field(offset));
766 break;
767 case T_FLOAT:
768 m->float_field_put(offset, orig_mirror->float_field(offset));
769 break;
770 case T_DOUBLE:
771 m->double_field_put(offset, orig_mirror->double_field(offset));
772 break;
773 default:
774 ShouldNotReachHere();
775 }
776 nfields ++;
777 }
778 }
779
780 oop class_data = java_lang_Class::class_data(orig_mirror);
781 java_lang_Class::set_class_data(m, class_data);
782 if (class_data != nullptr) {
783 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
784 assert(success, "sanity");
785 }
786
787 if (log_is_enabled(Debug, aot, init)) {
788 ResourceMark rm;
789 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
790 ik->is_hidden() ? " (hidden)" : "",
791 ik->is_enum_subclass() ? " (enum)" : "");
792 }
793 }
794
795 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
796 // We need to retain the identity_hash, because it may have been used by some hashtables
797 // in the shared heap.
798 if (!orig_mirror->fast_no_hash_check()) {
799 intptr_t src_hash = orig_mirror->identity_hash();
800 if (UseCompactObjectHeaders) {
801 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
802 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
803 } else {
804 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
805 }
806 assert(scratch_m->mark().is_unlocked(), "sanity");
807
808 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
809 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
810 }
811
812 if (CDSConfig::is_dumping_aot_linked_classes()) {
813 java_lang_Class::set_module(scratch_m, java_lang_Class::module(orig_mirror));
814 java_lang_Class::set_protection_domain(scratch_m, java_lang_Class::protection_domain(orig_mirror));
815 }
816
817 Klass* k = java_lang_Class::as_Klass(orig_mirror); // is null Universe::void_mirror();
818 if (CDSConfig::is_dumping_reflection_data() &&
819 k != nullptr && k->is_instance_klass() &&
820 java_lang_Class::reflection_data(orig_mirror) != nullptr &&
821 AOTConstantPoolResolver::can_archive_reflection_data(InstanceKlass::cast(k))) {
822 java_lang_Class::set_reflection_data(scratch_m, java_lang_Class::reflection_data(orig_mirror));
823 }
824 }
825
826 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
827 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
828 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
829 if (rr != nullptr && !ArchiveHeapWriter::is_too_large_to_archive(rr)) {
830 return HeapShared::scratch_resolved_references(src_ik->constants());
831 }
832 }
833 return nullptr;
834 }
835
836 void HeapShared::archive_strings() {
837 oop shared_strings_array = StringTable::init_shared_strings_array();
838 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, shared_strings_array);
839 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
840 StringTable::set_shared_strings_array_index(append_root(shared_strings_array));
841 }
842
843 int HeapShared::archive_exception_instance(oop exception) {
844 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
845 assert(success, "sanity");
846 return append_root(exception);
847 }
848
849 void HeapShared::mark_native_pointers(oop orig_obj) {
850 if (java_lang_Class::is_instance(orig_obj)) {
851 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::klass_offset());
852 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_Class::array_klass_offset());
853 } else if (java_lang_invoke_ResolvedMethodName::is_instance(orig_obj)) {
854 ArchiveHeapWriter::mark_native_pointer(orig_obj, java_lang_invoke_ResolvedMethodName::vmtarget_offset());
855 }
856 }
857
858 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
859 OopHandle oh(&src_obj);
860 CachedOopInfo* info = archived_object_cache()->get(oh);
861 assert(info != nullptr, "must be");
862 has_oop_pointers = info->has_oop_pointers();
863 has_native_pointers = info->has_native_pointers();
864 }
865
866 void HeapShared::set_has_native_pointers(oop src_obj) {
867 OopHandle oh(&src_obj);
868 CachedOopInfo* info = archived_object_cache()->get(oh);
869 assert(info != nullptr, "must be");
870 info->set_has_native_pointers();
871 }
872
873 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
874 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
875 void HeapShared::start_scanning_for_oops() {
876 {
877 NoSafepointVerifier nsv;
878
879 // The special subgraph doesn't belong to any class. We use Object_klass() here just
880 // for convenience.
881 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
882 _context = new GrowableArrayCHeap<const char*, mtClassShared>(250);
883
884 // Cache for recording where the archived objects are copied to
885 create_archived_object_cache();
886
887 if (UseCompressedOops || UseG1GC) {
888 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
889 UseCompressedOops ? p2i(CompressedOops::begin()) :
890 p2i((address)G1CollectedHeap::heap()->reserved().start()),
891 UseCompressedOops ? p2i(CompressedOops::end()) :
892 p2i((address)G1CollectedHeap::heap()->reserved().end()));
893 }
894
895 archive_subgraphs();
896 }
897
898 init_seen_objects_table();
899 Universe::archive_exception_instances();
900 }
901
902 void HeapShared::end_scanning_for_oops() {
903 archive_strings();
904 delete_seen_objects_table();
905 }
906
907 void HeapShared::write_heap(ArchiveHeapInfo *heap_info) {
908 {
909 NoSafepointVerifier nsv;
910 if (!SkipArchiveHeapVerification) {
911 CDSHeapVerifier::verify();
912 }
913 check_special_subgraph_classes();
914 }
915
916 StringTable::write_shared_table();
917 GrowableArrayCHeap<oop, mtClassShared>* roots = new GrowableArrayCHeap<oop, mtClassShared>(_pending_roots->length());
918 for (int i = 0; i < _pending_roots->length(); i++) {
919 roots->append(_pending_roots->at(i).resolve());
920 }
921 ArchiveHeapWriter::write(roots, heap_info);
922 delete roots;
923
924 ArchiveBuilder::OtherROAllocMark mark;
925 write_subgraph_info_table();
926 }
927
928 void HeapShared::scan_java_mirror(oop orig_mirror) {
929 oop m = scratch_java_mirror(orig_mirror);
930 if (m != nullptr) { // nullptr if for custom class loader
931 copy_java_mirror(orig_mirror, m);
932 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
933 assert(success, "sanity");
934
935 oop extra;
936 if ((extra = java_lang_Class::reflection_data(m)) != nullptr) {
937 success = archive_reachable_objects_from(1, _dump_time_special_subgraph, extra);
938 assert(success, "sanity");
939 }
940 }
941 }
942
943 void HeapShared::scan_java_class(Klass* orig_k) {
944 scan_java_mirror(orig_k->java_mirror());
945
946 if (orig_k->is_instance_klass()) {
947 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
948 orig_ik->constants()->prepare_resolved_references_for_archiving();
949 objArrayOop rr = get_archived_resolved_references(orig_ik);
950 if (rr != nullptr) {
951 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
952 assert(success, "must be");
953 }
954 }
955 }
956
957 void HeapShared::archive_subgraphs() {
958 assert(CDSConfig::is_dumping_heap(), "must be");
959
960 archive_object_subgraphs(archive_subgraph_entry_fields,
961 false /* is_full_module_graph */);
962
963 if (CDSConfig::is_dumping_full_module_graph()) {
964 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
965 true /* is_full_module_graph */);
966 Modules::verify_archived_modules();
967 }
968 }
969
970 //
971 // Subgraph archiving support
972 //
973 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
974 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
975
976 // Get the subgraph_info for Klass k. A new subgraph_info is created if
977 // there is no existing one for k. The subgraph_info records the "buffered"
978 // address of the class.
979 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
980 assert(CDSConfig::is_dumping_heap(), "dump time only");
981 bool created;
982 KlassSubGraphInfo* info =
983 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
984 &created);
985 assert(created, "must not initialize twice");
986 return info;
987 }
988
989 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
990 assert(CDSConfig::is_dumping_heap(), "dump time only");
991 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
992 assert(info != nullptr, "must have been initialized");
993 return info;
994 }
995
996 // Add an entry field to the current KlassSubGraphInfo.
997 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
998 assert(CDSConfig::is_dumping_heap(), "dump time only");
999 if (_subgraph_entry_fields == nullptr) {
1000 _subgraph_entry_fields =
1001 new (mtClass) GrowableArray<int>(10, mtClass);
1002 }
1003 _subgraph_entry_fields->append(static_field_offset);
1004 _subgraph_entry_fields->append(HeapShared::append_root(v));
1005 }
1006
1007 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1008 // Only objects of boot classes can be included in sub-graph.
1009 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1010 assert(CDSConfig::is_dumping_heap(), "dump time only");
1011
1012 if (_subgraph_object_klasses == nullptr) {
1013 _subgraph_object_klasses =
1014 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1015 }
1016
1017 if (_k == orig_k) {
1018 // Don't add the Klass containing the sub-graph to it's own klass
1019 // initialization list.
1020 return;
1021 }
1022
1023 if (orig_k->is_instance_klass()) {
1024 #ifdef ASSERT
1025 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1026 if (CDSConfig::is_dumping_method_handles()) {
1027 // -XX:AOTInitTestClass must be used carefully in regression tests to
1028 // include only classes that are safe to aot-initialize.
1029 assert(ik->class_loader() == nullptr ||
1030 HeapShared::is_lambda_proxy_klass(ik) ||
1031 AOTClassInitializer::has_test_class(),
1032 "we can archive only instances of boot classes or lambda proxy classes");
1033 } else {
1034 assert(ik->class_loader() == nullptr, "must be boot class");
1035 }
1036 #endif
1037 // vmClasses::xxx_klass() are not updated, need to check
1038 // the original Klass*
1039 if (orig_k == vmClasses::String_klass() ||
1040 orig_k == vmClasses::Object_klass()) {
1041 // Initialized early during VM initialization. No need to be added
1042 // to the sub-graph object class list.
1043 return;
1044 }
1045 check_allowed_klass(InstanceKlass::cast(orig_k));
1046 } else if (orig_k->is_objArray_klass()) {
1047 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1048 if (abk->is_instance_klass()) {
1049 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1050 "must be boot class");
1051 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1052 }
1053 if (orig_k == Universe::objectArrayKlass()) {
1054 // Initialized early during Universe::genesis. No need to be added
1055 // to the list.
1056 return;
1057 }
1058 } else {
1059 assert(orig_k->is_typeArray_klass(), "must be");
1060 // Primitive type arrays are created early during Universe::genesis.
1061 return;
1062 }
1063
1064 if (log_is_enabled(Debug, aot, heap)) {
1065 if (!_subgraph_object_klasses->contains(orig_k)) {
1066 ResourceMark rm;
1067 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1068 }
1069 }
1070
1071 _subgraph_object_klasses->append_if_missing(orig_k);
1072 _has_non_early_klasses |= is_non_early_klass(orig_k);
1073 }
1074
1075 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1076 #ifndef PRODUCT
1077 if (AOTClassInitializer::has_test_class()) {
1078 // The tests can cache arbitrary types of objects.
1079 return;
1080 }
1081 #endif
1082
1083 if (ik->module()->name() == vmSymbols::java_base()) {
1084 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1085 return;
1086 }
1087
1088 const char* lambda_msg = "";
1089 if (CDSConfig::is_dumping_method_handles()) {
1090 lambda_msg = ", or a lambda proxy class";
1091 if (HeapShared::is_lambda_proxy_klass(ik) &&
1092 (ik->class_loader() == nullptr ||
1093 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1094 ik->class_loader() == SystemDictionary::java_system_loader())) {
1095 return;
1096 }
1097 }
1098
1099 #ifndef PRODUCT
1100 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1101 // This class is loaded by ArchiveHeapTestClass
1102 return;
1103 }
1104 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1105 #else
1106 const char* testcls_msg = "";
1107 #endif
1108
1109 ResourceMark rm;
1110 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1111 ik->external_name(), lambda_msg, testcls_msg);
1112 AOTMetaspace::unrecoverable_writing_error();
1113 }
1114
1115 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1116 if (k->is_objArray_klass()) {
1117 k = ObjArrayKlass::cast(k)->bottom_klass();
1118 }
1119 if (k->is_instance_klass()) {
1120 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1121 ResourceMark rm;
1122 log_info(aot, heap)("non-early: %s", k->external_name());
1123 return true;
1124 } else {
1125 return false;
1126 }
1127 } else {
1128 return false;
1129 }
1130 }
1131
1132 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1133 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1134 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1135 _entry_field_records = nullptr;
1136 _subgraph_object_klasses = nullptr;
1137 _is_full_module_graph = info->is_full_module_graph();
1138
1139 if (_is_full_module_graph) {
1140 // Consider all classes referenced by the full module graph as early -- we will be
1141 // allocating objects of these classes during JVMTI early phase, so they cannot
1142 // be processed by (non-early) JVMTI ClassFileLoadHook
1143 _has_non_early_klasses = false;
1144 } else {
1145 _has_non_early_klasses = info->has_non_early_klasses();
1146 }
1147
1148 if (_has_non_early_klasses) {
1149 ResourceMark rm;
1150 log_info(aot, heap)(
1151 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1152 _k->external_name());
1153 }
1154
1155 // populate the entry fields
1156 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1157 if (entry_fields != nullptr) {
1158 int num_entry_fields = entry_fields->length();
1159 assert(num_entry_fields % 2 == 0, "sanity");
1160 _entry_field_records =
1161 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1162 for (int i = 0 ; i < num_entry_fields; i++) {
1163 _entry_field_records->at_put(i, entry_fields->at(i));
1164 }
1165 }
1166
1167 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1168 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1169 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1170 if (recorded_klasses != nullptr) {
1171 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1172 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1173 // that are not aot-inited.
1174 int num_to_copy = 0;
1175 for (int i = 0; i < recorded_klasses->length(); i++) {
1176 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1177 if (!subgraph_k->has_aot_initialized_mirror()) {
1178 num_to_copy ++;
1179 }
1180 }
1181
1182 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1183 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1184 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1185 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1186 if (subgraph_k->has_aot_initialized_mirror()) {
1187 continue;
1188 }
1189 if (log_is_enabled(Info, aot, heap)) {
1190 ResourceMark rm;
1191 const char* owner_name = is_special ? "<special>" : _k->external_name();
1192 if (subgraph_k->is_instance_klass()) {
1193 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1194 }
1195 log_info(aot, heap)(
1196 "Archived object klass %s (%2d) => %s",
1197 owner_name, n, subgraph_k->external_name());
1198 }
1199 _subgraph_object_klasses->at_put(n, subgraph_k);
1200 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1201 n++;
1202 }
1203 }
1204
1205 ArchivePtrMarker::mark_pointer(&_k);
1206 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1207 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1208 }
1209
1210 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1211 CompactHashtableWriter* _writer;
1212 public:
1213 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1214
1215 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1216 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1217 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1218 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1219 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1220 u4 delta = ArchiveBuilder::current()->any_to_offset_u4(record);
1221 _writer->add(hash, delta);
1222 }
1223 return true; // keep on iterating
1224 }
1225 };
1226
1227 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1228 ArchivedKlassSubGraphInfoRecord* record =
1229 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1230 record->init(info);
1231 if (info == _dump_time_special_subgraph) {
1232 _run_time_special_subgraph = record;
1233 }
1234 return record;
1235 }
1236
1237 // Build the records of archived subgraph infos, which include:
1238 // - Entry points to all subgraphs from the containing class mirror. The entry
1239 // points are static fields in the mirror. For each entry point, the field
1240 // offset, and value are recorded in the sub-graph
1241 // info. The value is stored back to the corresponding field at runtime.
1242 // - A list of klasses that need to be loaded/initialized before archived
1243 // java object sub-graph can be accessed at runtime.
1244 void HeapShared::write_subgraph_info_table() {
1245 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1246 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1247 CompactHashtableStats stats;
1248
1249 _run_time_subgraph_info_table.reset();
1250
1251 CompactHashtableWriter writer(d_table->_count, &stats);
1252 CopyKlassSubGraphInfoToArchive copy(&writer);
1253 d_table->iterate(©);
1254 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1255
1256 #ifndef PRODUCT
1257 if (ArchiveHeapTestClass != nullptr) {
1258 size_t len = strlen(ArchiveHeapTestClass) + 1;
1259 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1260 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1261 _archived_ArchiveHeapTestClass = array;
1262 }
1263 #endif
1264 if (log_is_enabled(Info, aot, heap)) {
1265 print_stats();
1266 }
1267 }
1268
1269 void HeapShared::add_root_segment(objArrayOop segment_oop) {
1270 assert(segment_oop != nullptr, "must be");
1271 assert(ArchiveHeapLoader::is_in_use(), "must be");
1272 if (_root_segments == nullptr) {
1273 _root_segments = new GrowableArrayCHeap<OopHandle, mtClassShared>(10);
1274 }
1275 _root_segments->push(OopHandle(Universe::vm_global(), segment_oop));
1276 }
1277
1278 void HeapShared::init_root_segment_sizes(int max_size_elems) {
1279 _root_segment_max_size_elems = max_size_elems;
1280 }
1281
1282 void HeapShared::serialize_tables(SerializeClosure* soc) {
1283
1284 #ifndef PRODUCT
1285 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1286 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1287 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1288 setup_test_class(_test_class_name);
1289 }
1290 #endif
1291
1292 _run_time_subgraph_info_table.serialize_header(soc);
1293 soc->do_ptr(&_run_time_special_subgraph);
1294 }
1295
1296 static void verify_the_heap(Klass* k, const char* which) {
1297 if (VerifyArchivedFields > 0) {
1298 ResourceMark rm;
1299 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1300 which, k->external_name());
1301
1302 VM_Verify verify_op;
1303 VMThread::execute(&verify_op);
1304
1305 if (VerifyArchivedFields > 1 && is_init_completed()) {
1306 // At this time, the oop->klass() of some archived objects in the heap may not
1307 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1308 // have enough information (object size, oop maps, etc) so that a GC can be safely
1309 // performed.
1310 //
1311 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1312 // to check for GC safety.
1313 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1314 which, k->external_name());
1315 FlagSetting fs1(VerifyBeforeGC, true);
1316 FlagSetting fs2(VerifyDuringGC, true);
1317 FlagSetting fs3(VerifyAfterGC, true);
1318 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1319 }
1320 }
1321 }
1322
1323 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1324 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1325 //
1326 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1327 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1328 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1329 void HeapShared::resolve_classes(JavaThread* current) {
1330 assert(CDSConfig::is_using_archive(), "runtime only!");
1331 if (!ArchiveHeapLoader::is_in_use()) {
1332 return; // nothing to do
1333 }
1334
1335 if (!CDSConfig::is_using_aot_linked_classes()) {
1336 assert( _run_time_special_subgraph != nullptr, "must be");
1337 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1338 if (klasses != nullptr) {
1339 for (int i = 0; i < klasses->length(); i++) {
1340 Klass* k = klasses->at(i);
1341 ExceptionMark em(current); // no exception can happen here
1342 resolve_or_init(k, /*do_init*/false, current);
1343 }
1344 }
1345 }
1346
1347 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1348 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1349 }
1350
1351 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1352 for (int i = 0; fields[i].valid(); i++) {
1353 ArchivableStaticFieldInfo* info = &fields[i];
1354 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1355 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1356 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1357 resolve_classes_for_subgraph_of(current, k);
1358 }
1359 }
1360
1361 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1362 JavaThread* THREAD = current;
1363 ExceptionMark em(THREAD);
1364 const ArchivedKlassSubGraphInfoRecord* record =
1365 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1366 if (HAS_PENDING_EXCEPTION) {
1367 CLEAR_PENDING_EXCEPTION;
1368 }
1369 if (record == nullptr) {
1370 clear_archived_roots_of(k);
1371 }
1372 }
1373
1374 static const char* java_lang_invoke_core_klasses[] = {
1375 "java/lang/invoke/Invokers$Holder",
1376 "java/lang/invoke/MethodHandle",
1377 "java/lang/invoke/MethodHandleNatives",
1378 "java/lang/invoke/DirectMethodHandle$Holder",
1379 "java/lang/invoke/DelegatingMethodHandle$Holder",
1380 "java/lang/invoke/LambdaForm$Holder",
1381 "java/lang/invoke/BoundMethodHandle$Species_L",
1382 };
1383
1384 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1385 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1386 int len = sizeof(java_lang_invoke_core_klasses)/sizeof(char*);
1387 for (int i = 0; i < len; i++) {
1388 resolve_or_init(java_lang_invoke_core_klasses[i], true, CHECK);
1389 }
1390 }
1391 }
1392
1393 bool HeapShared::is_core_java_lang_invoke_klass(InstanceKlass* klass) {
1394 // TODO: Crude, rewrite using Symbols or vmClasses instead
1395 ResourceMark rm;
1396 char* s2 = klass->name()->as_C_string();
1397 int len = sizeof(java_lang_invoke_core_klasses)/sizeof(char*);
1398 for (int i = 0; i < len; i++) {
1399 if (strcmp(java_lang_invoke_core_klasses[i], s2) == 0) {
1400 return true;
1401 }
1402 }
1403 return false;
1404 }
1405
1406 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1407 // - interned strings
1408 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1409 // - ConstantPool::resolved_references()
1410 // - Universe::<xxx>_exception_instance()
1411 //
1412 // For example, if this enum class is initialized at AOT cache assembly time:
1413 //
1414 // enum Fruit {
1415 // APPLE, ORANGE, BANANA;
1416 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1417 // }
1418 //
1419 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1420 // should be initialized before any Java code can access the Fruit class. Note that
1421 // HashSet itself doesn't necessary need to be an aot-initialized class.
1422 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1423 if (!ArchiveHeapLoader::is_in_use()) {
1424 return;
1425 }
1426
1427 assert( _run_time_special_subgraph != nullptr, "must be");
1428 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1429 if (klasses != nullptr) {
1430 for (int pass = 0; pass < 2; pass ++) {
1431 for (int i = 0; i < klasses->length(); i++) {
1432 Klass* k = klasses->at(i);
1433 if (k->class_loader_data() == nullptr) {
1434 // This class is not yet loaded. We will initialize it in a later phase.
1435 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1436 // but k is part of AOTLinkedClassCategory::BOOT2.
1437 continue;
1438 }
1439 if (k->class_loader() == class_loader()) {
1440 if (pass == 0) {
1441 if (k->is_instance_klass()) {
1442 InstanceKlass::cast(k)->link_class(CHECK);
1443 }
1444 } else {
1445 resolve_or_init(k, /*do_init*/true, CHECK);
1446 }
1447 }
1448 }
1449 }
1450 }
1451 }
1452
1453 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1454 JavaThread* THREAD = current;
1455 if (!ArchiveHeapLoader::is_in_use()) {
1456 return; // nothing to do
1457 }
1458
1459 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1460 !CDSConfig::is_using_optimized_module_handling() &&
1461 // archive was created with --module-path
1462 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1463 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1464 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1465 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1466 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1467 AOTClassLocationConfig::runtime()->num_module_paths());
1468 return;
1469 }
1470
1471 ExceptionMark em(THREAD);
1472 const ArchivedKlassSubGraphInfoRecord* record =
1473 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1474
1475 if (HAS_PENDING_EXCEPTION) {
1476 CLEAR_PENDING_EXCEPTION;
1477 // None of the field value will be set if there was an exception when initializing the classes.
1478 // The java code will not see any of the archived objects in the
1479 // subgraphs referenced from k in this case.
1480 return;
1481 }
1482
1483 if (record != nullptr) {
1484 init_archived_fields_for(k, record);
1485 }
1486 }
1487
1488 const ArchivedKlassSubGraphInfoRecord*
1489 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1490 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1491
1492 if (!k->in_aot_cache()) {
1493 return nullptr;
1494 }
1495 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1496 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1497
1498 #ifndef PRODUCT
1499 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1500 _test_class = k;
1501 _test_class_record = record;
1502 }
1503 #endif
1504
1505 // Initialize from archived data. Currently this is done only
1506 // during VM initialization time. No lock is needed.
1507 if (record == nullptr) {
1508 if (log_is_enabled(Info, aot, heap)) {
1509 ResourceMark rm(THREAD);
1510 log_info(aot, heap)("subgraph %s is not recorded",
1511 k->external_name());
1512 }
1513 return nullptr;
1514 } else {
1515 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1516 if (log_is_enabled(Info, aot, heap)) {
1517 ResourceMark rm(THREAD);
1518 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1519 k->external_name());
1520 }
1521 return nullptr;
1522 }
1523
1524 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1525 if (log_is_enabled(Info, aot, heap)) {
1526 ResourceMark rm(THREAD);
1527 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1528 k->external_name());
1529 }
1530 return nullptr;
1531 }
1532
1533 if (log_is_enabled(Info, aot, heap)) {
1534 ResourceMark rm;
1535 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1536 }
1537
1538 resolve_or_init(k, do_init, CHECK_NULL);
1539
1540 // Load/link/initialize the klasses of the objects in the subgraph.
1541 // nullptr class loader is used.
1542 Array<Klass*>* klasses = record->subgraph_object_klasses();
1543 if (klasses != nullptr) {
1544 for (int i = 0; i < klasses->length(); i++) {
1545 Klass* klass = klasses->at(i);
1546 if (!klass->in_aot_cache()) {
1547 return nullptr;
1548 }
1549 resolve_or_init(klass, do_init, CHECK_NULL);
1550 }
1551 }
1552 }
1553
1554 return record;
1555 }
1556
1557 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1558 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1559 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1560 if (k == nullptr) {
1561 return;
1562 }
1563 assert(k->defined_by_boot_loader(), "sanity");
1564 resolve_or_init(k, false, CHECK);
1565 if (do_init) {
1566 resolve_or_init(k, true, CHECK);
1567 }
1568 }
1569
1570 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1571 if (!do_init) {
1572 if (k->class_loader_data() == nullptr) {
1573 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1574 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1575 }
1576 } else {
1577 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1578 if (k->is_instance_klass()) {
1579 InstanceKlass* ik = InstanceKlass::cast(k);
1580 ik->initialize(CHECK);
1581 } else if (k->is_objArray_klass()) {
1582 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1583 oak->initialize(CHECK);
1584 }
1585 }
1586 }
1587
1588 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1589 verify_the_heap(k, "before");
1590
1591 // Load the subgraph entry fields from the record and store them back to
1592 // the corresponding fields within the mirror.
1593 oop m = k->java_mirror();
1594 Array<int>* entry_field_records = record->entry_field_records();
1595 if (entry_field_records != nullptr) {
1596 int efr_len = entry_field_records->length();
1597 assert(efr_len % 2 == 0, "sanity");
1598 for (int i = 0; i < efr_len; i += 2) {
1599 int field_offset = entry_field_records->at(i);
1600 int root_index = entry_field_records->at(i+1);
1601 oop v = get_root(root_index, /*clear=*/true);
1602 if (k->has_aot_initialized_mirror()) {
1603 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1604 } else {
1605 m->obj_field_put(field_offset, v);
1606 }
1607 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1608 }
1609
1610 // Done. Java code can see the archived sub-graphs referenced from k's
1611 // mirror after this point.
1612 if (log_is_enabled(Info, aot, heap)) {
1613 ResourceMark rm;
1614 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1615 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1616 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1617 }
1618 }
1619
1620 verify_the_heap(k, "after ");
1621 }
1622
1623 void HeapShared::clear_archived_roots_of(Klass* k) {
1624 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1625 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1626 if (record != nullptr) {
1627 Array<int>* entry_field_records = record->entry_field_records();
1628 if (entry_field_records != nullptr) {
1629 int efr_len = entry_field_records->length();
1630 assert(efr_len % 2 == 0, "sanity");
1631 for (int i = 0; i < efr_len; i += 2) {
1632 int root_index = entry_field_records->at(i+1);
1633 clear_root(root_index);
1634 }
1635 }
1636 }
1637 }
1638
1639 // Push all oop fields (or oop array elemenets in case of an objArray) in
1640 // _referencing_obj onto the _stack.
1641 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1642 PendingOopStack* _stack;
1643 GrowableArray<oop> _found_oop_fields;
1644 int _level;
1645 bool _record_klasses_only;
1646 KlassSubGraphInfo* _subgraph_info;
1647 oop _referencing_obj;
1648 bool _is_java_lang_ref;
1649 public:
1650 OopFieldPusher(PendingOopStack* stack,
1651 int level,
1652 bool record_klasses_only,
1653 KlassSubGraphInfo* subgraph_info,
1654 oop orig) :
1655 _stack(stack),
1656 _found_oop_fields(),
1657 _level(level),
1658 _record_klasses_only(record_klasses_only),
1659 _subgraph_info(subgraph_info),
1660 _referencing_obj(orig) {
1661 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1662 }
1663 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1664 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1665
1666 ~OopFieldPusher() {
1667 while (_found_oop_fields.length() > 0) {
1668 // This produces the exact same traversal order as the previous version
1669 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1670 // walking the oop fields in _referencing_obj by ascending field offsets.
1671 oop obj = _found_oop_fields.pop();
1672 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1673 }
1674 }
1675
1676 protected:
1677 template <class T> void do_oop_work(T *p) {
1678 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1679 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1680 if (!CompressedOops::is_null(obj)) {
1681 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1682 // Do not follow these fields. They will be cleared to null.
1683 return;
1684 }
1685
1686 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1687 ResourceMark rm;
1688 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1689 _referencing_obj->klass()->external_name(), field_offset,
1690 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1691 if (log_is_enabled(Trace, aot, heap)) {
1692 LogTarget(Trace, aot, heap) log;
1693 LogStream out(log);
1694 obj->print_on(&out);
1695 }
1696 }
1697
1698 _found_oop_fields.push(obj);
1699 }
1700 }
1701
1702 public:
1703 oop referencing_obj() { return _referencing_obj; }
1704 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1705 };
1706
1707 // Checks if an oop has any non-null oop fields
1708 class PointsToOopsChecker : public BasicOopIterateClosure {
1709 bool _result;
1710
1711 template <class T> void check(T *p) {
1712 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1713 }
1714
1715 public:
1716 PointsToOopsChecker() : _result(false) {}
1717 void do_oop(narrowOop *p) { check(p); }
1718 void do_oop( oop *p) { check(p); }
1719 bool result() { return _result; }
1720 };
1721
1722 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1723 PointsToOopsChecker points_to_oops_checker;
1724 obj->oop_iterate(&points_to_oops_checker);
1725 return CachedOopInfo(OopHandle(Universe::vm_global(), referrer), points_to_oops_checker.result());
1726 }
1727
1728 void HeapShared::init_box_classes(TRAPS) {
1729 if (ArchiveHeapLoader::is_in_use()) {
1730 vmClasses::Boolean_klass()->initialize(CHECK);
1731 vmClasses::Character_klass()->initialize(CHECK);
1732 vmClasses::Float_klass()->initialize(CHECK);
1733 vmClasses::Double_klass()->initialize(CHECK);
1734 vmClasses::Byte_klass()->initialize(CHECK);
1735 vmClasses::Short_klass()->initialize(CHECK);
1736 vmClasses::Integer_klass()->initialize(CHECK);
1737 vmClasses::Long_klass()->initialize(CHECK);
1738 vmClasses::Void_klass()->initialize(CHECK);
1739 }
1740 }
1741
1742 void HeapShared::exit_on_error() {
1743 if (_context != nullptr) {
1744 ResourceMark rm;
1745 LogStream ls(Log(cds, heap)::error());
1746 ls.print_cr("Context");
1747 for (int i = 0; i < _context->length(); i++) {
1748 const char* s = _context->at(i);
1749 ls.print_cr("- %s", s);
1750 }
1751 }
1752 debug_trace();
1753 AOTMetaspace::unrecoverable_writing_error();
1754 }
1755
1756 // (1) If orig_obj has not been archived yet, archive it.
1757 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1758 // trace all objects that are reachable from it, and make sure these objects are archived.
1759 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1760 // were already archived when this function is called)
1761 bool HeapShared::archive_reachable_objects_from(int level,
1762 KlassSubGraphInfo* subgraph_info,
1763 oop orig_obj) {
1764 assert(orig_obj != nullptr, "must be");
1765 PendingOopStack stack;
1766 stack.push(PendingOop(orig_obj, nullptr, level));
1767
1768 while (stack.length() > 0) {
1769 PendingOop po = stack.pop();
1770 _object_being_archived = po;
1771 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1772 _object_being_archived = PendingOop();
1773
1774 if (!status) {
1775 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1776 // as the Java code will take care of initializing this field dynamically.
1777 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1778 return false;
1779 }
1780 }
1781
1782 return true;
1783 }
1784
1785 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1786 oop orig_obj, oop referrer) {
1787 assert(orig_obj != nullptr, "must be");
1788 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1789 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1790 // If you get an error here, you probably made a change in the JDK library that has added
1791 // these objects that are referenced (directly or indirectly) by static fields.
1792 ResourceMark rm;
1793 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1794 debug_trace();
1795 AOTMetaspace::unrecoverable_writing_error();
1796 }
1797
1798 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1799 ResourceMark rm;
1800 LogTarget(Debug, aot, heap) log;
1801 LogStream out(log);
1802 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1803 Klass* k = java_lang_Class::as_Klass(orig_obj);
1804 if (k != nullptr) {
1805 out.print("%s", k->external_name());
1806 } else {
1807 out.print("primitive");
1808 }
1809 out.print_cr("; scratch mirror = " PTR_FORMAT,
1810 p2i(scratch_java_mirror(orig_obj)));
1811 }
1812
1813 if (java_lang_Class::is_instance(orig_obj)) {
1814 Klass* k = java_lang_Class::as_Klass(orig_obj);
1815 if (RegeneratedClasses::has_been_regenerated(k)) {
1816 orig_obj = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
1817 }
1818 }
1819
1820 if (CDSConfig::is_initing_classes_at_dump_time()) {
1821 if (java_lang_Class::is_instance(orig_obj)) {
1822 orig_obj = scratch_java_mirror(orig_obj);
1823 assert(orig_obj != nullptr, "must be archived");
1824 }
1825 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1826 // Without CDSConfig::is_initing_classes_at_dump_time(), we only allow archived objects to
1827 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1828 // very early by HeapShared::init_box_classes().
1829 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1830 || java_lang_Class::is_primitive(orig_obj)
1831 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1832 || orig_obj == vmClasses::Character_klass()->java_mirror()
1833 || orig_obj == vmClasses::Float_klass()->java_mirror()
1834 || orig_obj == vmClasses::Double_klass()->java_mirror()
1835 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1836 || orig_obj == vmClasses::Short_klass()->java_mirror()
1837 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1838 || orig_obj == vmClasses::Long_klass()->java_mirror()
1839 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1840 orig_obj = scratch_java_mirror(orig_obj);
1841 assert(orig_obj != nullptr, "must be archived");
1842 } else {
1843 // If you get an error here, you probably made a change in the JDK library that has added a Class
1844 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1845 // defined at the top of this file.
1846 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1847 debug_trace();
1848 AOTMetaspace::unrecoverable_writing_error();
1849 }
1850 }
1851
1852 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1853 // orig_obj has already been archived and traced. Nothing more to do.
1854 return true;
1855 } else {
1856 set_has_been_seen_during_subgraph_recording(orig_obj);
1857 }
1858
1859 bool already_archived = has_been_archived(orig_obj);
1860 bool record_klasses_only = already_archived;
1861 if (!already_archived) {
1862 ++_num_new_archived_objs;
1863 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1864 // Skip archiving the sub-graph referenced from the current entry field.
1865 ResourceMark rm;
1866 log_error(aot, heap)(
1867 "Cannot archive the sub-graph referenced from %s object ("
1868 PTR_FORMAT ") size %zu, skipped.",
1869 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1870 if (level == 1) {
1871 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1872 // as the Java code will take care of initializing this field dynamically.
1873 return false;
1874 } else {
1875 // We don't know how to handle an object that has been archived, but some of its reachable
1876 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1877 // we have a real use case.
1878 AOTMetaspace::unrecoverable_writing_error();
1879 }
1880 }
1881 }
1882
1883 Klass *orig_k = orig_obj->klass();
1884 subgraph_info->add_subgraph_object_klass(orig_k);
1885
1886 {
1887 // Find all the oops that are referenced by orig_obj, push them onto the stack
1888 // so we can work on them next.
1889 ResourceMark rm;
1890 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1891 orig_obj->oop_iterate(&pusher);
1892 }
1893
1894 if (CDSConfig::is_initing_classes_at_dump_time()) {
1895 // The classes of all archived enum instances have been marked as aot-init,
1896 // so there's nothing else to be done in the production run.
1897 } else {
1898 // This is legacy support for enum classes before JEP 483 -- we cannot rerun
1899 // the enum's <clinit> in the production run, so special handling is needed.
1900 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1901 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1902 }
1903 }
1904
1905 return true;
1906 }
1907
1908 //
1909 // Start from the given static field in a java mirror and archive the
1910 // complete sub-graph of java heap objects that are reached directly
1911 // or indirectly from the starting object by following references.
1912 // Sub-graph archiving restrictions (current):
1913 //
1914 // - All classes of objects in the archived sub-graph (including the
1915 // entry class) must be boot class only.
1916 // - No java.lang.Class instance (java mirror) can be included inside
1917 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1918 //
1919 // The Java heap object sub-graph archiving process (see OopFieldPusher):
1920 //
1921 // 1) Java object sub-graph archiving starts from a given static field
1922 // within a Class instance (java mirror). If the static field is a
1923 // reference field and points to a non-null java object, proceed to
1924 // the next step.
1925 //
1926 // 2) Archives the referenced java object. If an archived copy of the
1927 // current object already exists, updates the pointer in the archived
1928 // copy of the referencing object to point to the current archived object.
1929 // Otherwise, proceed to the next step.
1930 //
1931 // 3) Follows all references within the current java object and recursively
1932 // archive the sub-graph of objects starting from each reference.
1933 //
1934 // 4) Updates the pointer in the archived copy of referencing object to
1935 // point to the current archived object.
1936 //
1937 // 5) The Klass of the current java object is added to the list of Klasses
1938 // for loading and initializing before any object in the archived graph can
1939 // be accessed at runtime.
1940 //
1941 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1942 const char* klass_name,
1943 int field_offset,
1944 const char* field_name) {
1945 assert(CDSConfig::is_dumping_heap(), "dump time only");
1946 assert(k->defined_by_boot_loader(), "must be boot class");
1947
1948 oop m = k->java_mirror();
1949
1950 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1951 oop f = m->obj_field(field_offset);
1952
1953 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1954
1955 if (!CompressedOops::is_null(f)) {
1956 if (log_is_enabled(Trace, aot, heap)) {
1957 LogTarget(Trace, aot, heap) log;
1958 LogStream out(log);
1959 f->print_on(&out);
1960 }
1961
1962 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1963 if (!success) {
1964 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1965 klass_name, field_name);
1966 } else {
1967 // Note: the field value is not preserved in the archived mirror.
1968 // Record the field as a new subGraph entry point. The recorded
1969 // information is restored from the archive at runtime.
1970 subgraph_info->add_subgraph_entry_field(field_offset, f);
1971 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1972 }
1973 } else {
1974 // The field contains null, we still need to record the entry point,
1975 // so it can be restored at runtime.
1976 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
1977 }
1978 }
1979
1980 #ifndef PRODUCT
1981 class VerifySharedOopClosure: public BasicOopIterateClosure {
1982 public:
1983 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
1984 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
1985
1986 protected:
1987 template <class T> void do_oop_work(T *p) {
1988 oop obj = RawAccess<>::oop_load(p);
1989 if (!CompressedOops::is_null(obj)) {
1990 HeapShared::verify_reachable_objects_from(obj);
1991 }
1992 }
1993 };
1994
1995 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
1996 assert(CDSConfig::is_dumping_heap(), "dump time only");
1997 assert(k->defined_by_boot_loader(), "must be boot class");
1998
1999 oop m = k->java_mirror();
2000 oop f = m->obj_field(field_offset);
2001 if (!CompressedOops::is_null(f)) {
2002 verify_subgraph_from(f);
2003 }
2004 }
2005
2006 void HeapShared::verify_subgraph_from(oop orig_obj) {
2007 if (!has_been_archived(orig_obj)) {
2008 // It's OK for the root of a subgraph to be not archived. See comments in
2009 // archive_reachable_objects_from().
2010 return;
2011 }
2012
2013 // Verify that all objects reachable from orig_obj are archived.
2014 init_seen_objects_table();
2015 verify_reachable_objects_from(orig_obj);
2016 delete_seen_objects_table();
2017 }
2018
2019 void HeapShared::verify_reachable_objects_from(oop obj) {
2020 _num_total_verifications ++;
2021 if (java_lang_Class::is_instance(obj)) {
2022 Klass* k = java_lang_Class::as_Klass(obj);
2023 if (RegeneratedClasses::has_been_regenerated(k)) {
2024 k = RegeneratedClasses::get_regenerated_object(k);
2025 obj = k->java_mirror();
2026 }
2027 obj = scratch_java_mirror(obj);
2028 assert(obj != nullptr, "must be");
2029 }
2030 if (!has_been_seen_during_subgraph_recording(obj)) {
2031 set_has_been_seen_during_subgraph_recording(obj);
2032 assert(has_been_archived(obj), "must be");
2033 VerifySharedOopClosure walker;
2034 obj->oop_iterate(&walker);
2035 }
2036 }
2037 #endif
2038
2039 void HeapShared::check_special_subgraph_classes() {
2040 if (CDSConfig::is_initing_classes_at_dump_time()) {
2041 // We can have aot-initialized classes (such as Enums) that can reference objects
2042 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
2043 // aot-initialize classes that are "safe".
2044 //
2045 // TODO: we need an automatic tool that checks the safety of aot-initialized
2046 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
2047 return;
2048 } else {
2049 // In this case, the special subgraph should contain a few specific types
2050 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
2051 int num = klasses->length();
2052 for (int i = 0; i < num; i++) {
2053 Klass* subgraph_k = klasses->at(i);
2054 Symbol* name = subgraph_k->name();
2055 if (subgraph_k->is_instance_klass() &&
2056 name != vmSymbols::java_lang_Class() &&
2057 name != vmSymbols::java_lang_String() &&
2058 name != vmSymbols::java_lang_ArithmeticException() &&
2059 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
2060 name != vmSymbols::java_lang_ArrayStoreException() &&
2061 name != vmSymbols::java_lang_ClassCastException() &&
2062 name != vmSymbols::java_lang_InternalError() &&
2063 name != vmSymbols::java_lang_NullPointerException()) {
2064 ResourceMark rm;
2065 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
2066 }
2067 }
2068 }
2069 }
2070
2071 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2072 HeapShared::PendingOop HeapShared::_object_being_archived;
2073 int HeapShared::_num_new_walked_objs;
2074 int HeapShared::_num_new_archived_objs;
2075 int HeapShared::_num_old_recorded_klasses;
2076
2077 int HeapShared::_num_total_subgraph_recordings = 0;
2078 int HeapShared::_num_total_walked_objs = 0;
2079 int HeapShared::_num_total_archived_objs = 0;
2080 int HeapShared::_num_total_recorded_klasses = 0;
2081 int HeapShared::_num_total_verifications = 0;
2082
2083 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2084 return _seen_objects_table->get(obj) != nullptr;
2085 }
2086
2087 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2088 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2089 _seen_objects_table->put_when_absent(obj, true);
2090 _seen_objects_table->maybe_grow();
2091 ++ _num_new_walked_objs;
2092 }
2093
2094 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2095 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2096 init_subgraph_info(k, is_full_module_graph);
2097 init_seen_objects_table();
2098 _num_new_walked_objs = 0;
2099 _num_new_archived_objs = 0;
2100 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2101 }
2102
2103 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2104 int num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2105 _num_old_recorded_klasses;
2106 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2107 "walked %d objs, archived %d new objs, recorded %d classes",
2108 class_name, _num_new_walked_objs, _num_new_archived_objs,
2109 num_new_recorded_klasses);
2110
2111 delete_seen_objects_table();
2112
2113 _num_total_subgraph_recordings ++;
2114 _num_total_walked_objs += _num_new_walked_objs;
2115 _num_total_archived_objs += _num_new_archived_objs;
2116 _num_total_recorded_klasses += num_new_recorded_klasses;
2117 }
2118
2119 class ArchivableStaticFieldFinder: public FieldClosure {
2120 InstanceKlass* _ik;
2121 Symbol* _field_name;
2122 bool _found;
2123 int _offset;
2124 public:
2125 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2126 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2127
2128 virtual void do_field(fieldDescriptor* fd) {
2129 if (fd->name() == _field_name) {
2130 assert(!_found, "fields can never be overloaded");
2131 if (is_reference_type(fd->field_type())) {
2132 _found = true;
2133 _offset = fd->offset();
2134 }
2135 }
2136 }
2137 bool found() { return _found; }
2138 int offset() { return _offset; }
2139 };
2140
2141 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2142 TRAPS) {
2143 for (int i = 0; fields[i].valid(); i++) {
2144 ArchivableStaticFieldInfo* info = &fields[i];
2145 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2146 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2147 ResourceMark rm; // for stringStream::as_string() etc.
2148
2149 #ifndef PRODUCT
2150 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2151 const char* test_class_name = ArchiveHeapTestClass;
2152 #else
2153 bool is_test_class = false;
2154 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2155 #endif
2156
2157 if (is_test_class) {
2158 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2159 }
2160
2161 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2162 if (HAS_PENDING_EXCEPTION) {
2163 CLEAR_PENDING_EXCEPTION;
2164 stringStream st;
2165 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2166 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2167 }
2168
2169 if (!k->is_instance_klass()) {
2170 stringStream st;
2171 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2172 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2173 }
2174
2175 InstanceKlass* ik = InstanceKlass::cast(k);
2176 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2177 "Only support boot classes");
2178
2179 if (is_test_class) {
2180 if (ik->module()->is_named()) {
2181 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2182 // core-lib classes. You need to at least append to the bootclasspath.
2183 stringStream st;
2184 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2185 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2186 }
2187
2188 if (ik->package() != nullptr) {
2189 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2190 stringStream st;
2191 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2192 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2193 }
2194 } else {
2195 if (ik->module()->name() != vmSymbols::java_base()) {
2196 // We don't want to deal with cases when a module is unavailable at runtime.
2197 // FUTURE -- load from archived heap only when module graph has not changed
2198 // between dump and runtime.
2199 stringStream st;
2200 st.print("%s is not in java.base module", info->klass_name);
2201 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2202 }
2203 }
2204
2205 if (is_test_class) {
2206 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2207 }
2208 ik->initialize(CHECK);
2209
2210 ArchivableStaticFieldFinder finder(ik, field_name);
2211 ik->do_local_static_fields(&finder);
2212 if (!finder.found()) {
2213 stringStream st;
2214 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2215 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2216 }
2217
2218 info->klass = ik;
2219 info->offset = finder.offset();
2220 }
2221 }
2222
2223 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2224 assert(CDSConfig::is_dumping_heap(), "must be");
2225 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2226 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2227 if (CDSConfig::is_dumping_full_module_graph()) {
2228 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2229 }
2230 }
2231
2232 #ifndef PRODUCT
2233 void HeapShared::setup_test_class(const char* test_class_name) {
2234 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2235 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2236 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2237 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2238
2239 if (test_class_name != nullptr) {
2240 p[num_slots - 2].klass_name = test_class_name;
2241 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2242 }
2243 }
2244
2245 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2246 // during runtime. This may be called before the module system is initialized so
2247 // we cannot rely on InstanceKlass::module(), etc.
2248 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2249 if (_test_class != nullptr) {
2250 if (ik == _test_class) {
2251 return true;
2252 }
2253 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2254 if (klasses == nullptr) {
2255 return false;
2256 }
2257
2258 for (int i = 0; i < klasses->length(); i++) {
2259 Klass* k = klasses->at(i);
2260 if (k == ik) {
2261 Symbol* name;
2262 if (k->is_instance_klass()) {
2263 name = InstanceKlass::cast(k)->name();
2264 } else if (k->is_objArray_klass()) {
2265 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2266 if (!bk->is_instance_klass()) {
2267 return false;
2268 }
2269 name = bk->name();
2270 } else {
2271 return false;
2272 }
2273
2274 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2275 // to be:
2276 // (A) java.base classes (which must not be in the unnamed module)
2277 // (B) test classes which must be in the unnamed package of the unnamed module.
2278 // So if we see a '/' character in the class name, it must be in (A);
2279 // otherwise it must be in (B).
2280 if (name->index_of_at(0, "/", 1) >= 0) {
2281 return false; // (A)
2282 }
2283
2284 return true; // (B)
2285 }
2286 }
2287 }
2288
2289 return false;
2290 }
2291
2292 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2293 Klass* k = _test_class;
2294 if (k != nullptr && ArchiveHeapLoader::is_in_use()) {
2295 JavaThread* THREAD = current;
2296 ExceptionMark em(THREAD);
2297 const ArchivedKlassSubGraphInfoRecord* record =
2298 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2299
2300 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2301 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2302 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2303 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2304 if (record != nullptr) {
2305 init_archived_fields_for(k, record);
2306 }
2307 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2308 }
2309 }
2310 #endif
2311
2312 void HeapShared::init_for_dumping(TRAPS) {
2313 if (CDSConfig::is_dumping_heap()) {
2314 setup_test_class(ArchiveHeapTestClass);
2315 _dumped_interned_strings = new (mtClass)DumpedInternedStrings(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
2316 init_subgraph_entry_fields(CHECK);
2317 }
2318 }
2319
2320 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2321 bool is_full_module_graph) {
2322 _num_total_subgraph_recordings = 0;
2323 _num_total_walked_objs = 0;
2324 _num_total_archived_objs = 0;
2325 _num_total_recorded_klasses = 0;
2326 _num_total_verifications = 0;
2327
2328 // For each class X that has one or more archived fields:
2329 // [1] Dump the subgraph of each archived field
2330 // [2] Create a list of all the class of the objects that can be reached
2331 // by any of these static fields.
2332 // At runtime, these classes are initialized before X's archived fields
2333 // are restored by HeapShared::initialize_from_archived_subgraph().
2334 for (int i = 0; fields[i].valid(); ) {
2335 ArchivableStaticFieldInfo* info = &fields[i];
2336 const char* klass_name = info->klass_name;
2337 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2338
2339 ContextMark cm(klass_name);
2340 // If you have specified consecutive fields of the same klass in
2341 // fields[], these will be archived in the same
2342 // {start_recording_subgraph ... done_recording_subgraph} pass to
2343 // save time.
2344 for (; fields[i].valid(); i++) {
2345 ArchivableStaticFieldInfo* f = &fields[i];
2346 if (f->klass_name != klass_name) {
2347 break;
2348 }
2349
2350 ContextMark cm(f->field_name);
2351 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2352 f->offset, f->field_name);
2353 }
2354 done_recording_subgraph(info->klass, klass_name);
2355 }
2356
2357 log_info(aot, heap)("Archived subgraph records = %d",
2358 _num_total_subgraph_recordings);
2359 log_info(aot, heap)(" Walked %d objects", _num_total_walked_objs);
2360 log_info(aot, heap)(" Archived %d objects", _num_total_archived_objs);
2361 log_info(aot, heap)(" Recorded %d klasses", _num_total_recorded_klasses);
2362
2363 #ifndef PRODUCT
2364 for (int i = 0; fields[i].valid(); i++) {
2365 ArchivableStaticFieldInfo* f = &fields[i];
2366 verify_subgraph_from_static_field(f->klass, f->offset);
2367 }
2368 log_info(aot, heap)(" Verified %d references", _num_total_verifications);
2369 #endif
2370 }
2371
2372 // Keep track of the contents of the archived interned string table. This table
2373 // is used only by CDSHeapVerifier.
2374 void HeapShared::add_to_dumped_interned_strings(oop string) {
2375 assert_at_safepoint(); // DumpedInternedStrings uses raw oops
2376 assert(!ArchiveHeapWriter::is_string_too_large_to_archive(string), "must be");
2377 bool created;
2378 _dumped_interned_strings->put_if_absent(string, true, &created);
2379 if (created) {
2380 // Prevent string deduplication from changing the value field to
2381 // something not in the archive.
2382 java_lang_String::set_deduplication_forbidden(string);
2383 _dumped_interned_strings->maybe_grow();
2384 }
2385 }
2386
2387 bool HeapShared::is_dumped_interned_string(oop o) {
2388 return _dumped_interned_strings->get(o) != nullptr;
2389 }
2390
2391 // These tables should be used only within the CDS safepoint, so
2392 // delete them before we exit the safepoint. Otherwise the table will
2393 // contain bad oops after a GC.
2394 void HeapShared::delete_tables_with_raw_oops() {
2395 assert(_seen_objects_table == nullptr, "should have been deleted");
2396
2397 delete _dumped_interned_strings;
2398 _dumped_interned_strings = nullptr;
2399
2400 ArchiveHeapWriter::delete_tables_with_raw_oops();
2401 }
2402
2403 void HeapShared::debug_trace() {
2404 ResourceMark rm;
2405 oop referrer = _object_being_archived.referrer();
2406 if (referrer != nullptr) {
2407 LogStream ls(Log(aot, heap)::error());
2408 ls.print_cr("Reference trace");
2409 CDSHeapVerifier::trace_to_root(&ls, referrer);
2410 }
2411 }
2412
2413 #ifndef PRODUCT
2414 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2415 // region. This way we can quickly relocate all the pointers without using
2416 // BasicOopIterateClosure at runtime.
2417 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2418 void* _start;
2419 BitMap *_oopmap;
2420 int _num_total_oops;
2421 int _num_null_oops;
2422 public:
2423 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2424 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2425
2426 virtual void do_oop(narrowOop* p) {
2427 assert(UseCompressedOops, "sanity");
2428 _num_total_oops ++;
2429 narrowOop v = *p;
2430 if (!CompressedOops::is_null(v)) {
2431 size_t idx = p - (narrowOop*)_start;
2432 _oopmap->set_bit(idx);
2433 } else {
2434 _num_null_oops ++;
2435 }
2436 }
2437 virtual void do_oop(oop* p) {
2438 assert(!UseCompressedOops, "sanity");
2439 _num_total_oops ++;
2440 if ((*p) != nullptr) {
2441 size_t idx = p - (oop*)_start;
2442 _oopmap->set_bit(idx);
2443 } else {
2444 _num_null_oops ++;
2445 }
2446 }
2447 int num_total_oops() const { return _num_total_oops; }
2448 int num_null_oops() const { return _num_null_oops; }
2449 };
2450 #endif
2451
2452 void HeapShared::count_allocation(size_t size) {
2453 _total_obj_count ++;
2454 _total_obj_size += size;
2455 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2456 if (size <= (size_t(1) << i)) {
2457 _alloc_count[i] ++;
2458 _alloc_size[i] += size;
2459 return;
2460 }
2461 }
2462 }
2463
2464 static double avg_size(size_t size, size_t count) {
2465 double avg = 0;
2466 if (count > 0) {
2467 avg = double(size * HeapWordSize) / double(count);
2468 }
2469 return avg;
2470 }
2471
2472 void HeapShared::print_stats() {
2473 size_t huge_count = _total_obj_count;
2474 size_t huge_size = _total_obj_size;
2475
2476 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2477 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2478 size_t count = _alloc_count[i];
2479 size_t size = _alloc_size[i];
2480 log_info(aot, heap)("%8zu objects are <= %-6zu"
2481 " bytes (total %8zu bytes, avg %8.1f bytes)",
2482 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2483 huge_count -= count;
2484 huge_size -= size;
2485 }
2486
2487 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2488 ", avg %8.1f bytes)",
2489 huge_count, huge_size * HeapWordSize,
2490 avg_size(huge_size, huge_count));
2491 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2492 ", avg %8.1f bytes)",
2493 _total_obj_count, _total_obj_size * HeapWordSize,
2494 avg_size(_total_obj_size, _total_obj_count));
2495 }
2496
2497 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2498 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2499 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2500 if (k == nullptr) {
2501 return false;
2502 } else {
2503 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2504 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2505 fieldDescriptor fd;
2506 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2507 oop m = k->java_mirror();
2508 oop f = m->obj_field(fd.offset());
2509 if (CompressedOops::is_null(f)) {
2510 return false;
2511 }
2512 } else {
2513 return false;
2514 }
2515 }
2516 return true;
2517 }
2518
2519 #endif // INCLUDE_CDS_JAVA_HEAP